Over on MLS, there’s a long thread (too long to copy) with posts by my pal Gigawat about his PCB for controlling a fan-driven smoke unit, like the $45 Train-Li. He didn’t like the way it was done on his loco so he made his own.
Pete, you know I’ve been on that thread, was there any commitment to price and availability?
By the way, if he set it up for “autochuff” and it could drive the chuff input of a Dallee board, for example, THEN you would have a low cost solution, sound and pulsed smoke.
Greg
I admit to not having read the thread completely, and not understanding half of what I did read, but do you really need those electronics? Seems to me that you could get the same result by putting a reed switch in the fan circuit, influenced by the same magnets that influence the chuff. It could even be the same reed switch (I think). As the reed switch closes, the fan is activated, producing a puff of “smoke.”
Steve Featherkile said:
I admit to not having read the thread completely, and not understanding half of what I did read, but do you really need those electronics? Seems to me that you could get the same result by putting a reed switch in the fan circuit, influenced by the same magnets that influence the chuff. It could even be the same reed switch (I think). As the reed switch closes, the fan is activated, producing a puff of “smoke.”
See my replies on the other site. 
Yes, the fan draw about 1/2 amp… that might be too much for some reeds, but there are indeed ones that work.
You also will want a “kickback” diode and capacitor in the circuit to protect the reed, because of the inductive load, and high inrush current (it’s a motor)
Of course you cannot get any of the fancy things like longer duration at slow speeds, more fan speed under heavy load, and no autochuff.
Greg
" but do you really need those electronics? Seems to me that you could get the same result by putting a reed switch in the fan circuit,"
Steve,
Yes, you probably could, and after plenty of trial and error, plus burning up a couple of smoke units, you’ll have a working smoker.
What gigawat did is produce a programmable, general purpose interface because he wasn’t satisfied with the Phoenix or the Bachmann smoke unit. If you watch his video, it will handle anything from 6-32V, and can be connected to a computer if you want to tune the parameters for a different smoke unit.
He did all the work and made a tiny device. You don’t have to use it!
Hey, I just axed a question, you don’t need to take me to the woodshed. Its all PFM, anyway. 
Steve Featherkile said:
Hey, I just axed a question, you don’t need to take me to the woodshed. Its all PFM, anyway.
Wasn’t trying to take you to the woodshed, and in fact I agree with you. I figured that most here frequent both sites and would save some space.
But, here from other site are my responses:
Actually would be fairly easy to do in dc.
Run the track voltage to the generator though a resistor for reduced output. Use a low voltage regulator and trigger a low voltage relay off the chuff contact/reed switch-magnet to let the full voltage flow to the generator for the puffs.
An alternative that does not require a chuff sensor could be to use a low voltage color organ to drive the smoke generator. This is pulsed from the chuff speaker. Rather than a light bulb, the smoke generator would be pulsed.
It may require an onboard power source for this one, but an enterprising person could make something like this work.
http://www.allelectronics.com/make-a…gan-kit/1.html
Quote:
Originally Posted by trainstrainstrains 
Greg, Toddalin, nice if you would both post here the electrical schematics of your personal solutions to the synchronized shuff puff sufficiently clearly so that a layman could easily construct them.
This is getting rather complex with Thomas Jefferson and all.
I am learning from all this that there are a few different products on the market to choose how to synchronize sound and smoke, also that I’m not the only one who is in the situation of not wanting to throw away recently bought and meticulously installed sound cards that not being the best do work. That therefore would prefer at least for the time being an inexpensive solution that would enhance the equipment we already have.
The link provided the schematic. It would be a matter of connecting the unit at the speaker and using the smoke unit as the “light.”
Personally, I would first try using track power instead of a battery. Because the unit accepts both a/c and d/c, it shouldn’t need rectification and because it can take 24 volts, there shouldn’t be a concern about over-powering it. Maybe there is “effect” even with less than 12 volts on the input.
Alternatively, an on-board battery could power the unit and smoke generator so the smoke output remains constant regardless of track voltage and only the chuff/puff rate changes with speed.
But I still think the easiest (and certainly the cheapest) way to do this is to use a 3 volt relay with two AA batteries to power it. The relay would be activated off the chuff reed switch, or you could set up a reed switch/magnet assembly on a wheel/axle. The relay contacts would let full power flow to the smoke generator and a “by-pass” resistor would allow for the unit to “stay warm” when full power is not flowing.
You can/should be able to simultaneously use a chuff reed/leaf switch to trigger both the sound system and relay providing that you use the batteries because this is akin to running the system through a common ground.
For the smoke motor to give great puffs, the circuit needs a ‘brake’ to stop the motor from free wheeling when the power is off.
I believe the decoders do this.
I checked a bit and I don’t think most do this. You need to short the motor output or even better apply reverse voltage.
I know the QSI just pulses. The only system I’ve seen evidence of what MAY be motor braking is the MTH DCS system.
Greg
Or, maybe, if you made a shutter mechanism that blocked the fan, and then unblocked the fan when it was to pulse the smoke. A small servo could do that.
Would that work?
Probably not, the heater depends on the air flow to not overheat.
Ok Greg, but stopping the fan would also deprive the unit of airflow.
On the old, I mean old, Tyco locomotives, they had a puffer (for lack of better term) attached to one of the driver axles. It was like a syringe body, and once per revolution it would force air up through the stack and create a puff of smoke. Now this system was on a toy, and only created one puff per revolution. But if it were driven differently it could do 2 or 4 puffs per revolution.
Its just an idea I had been playing with in my (feeble) mind for a while.